13.3 Mutations

Understand Key Concepts

  1. Changes in DNA sequences that affect genetic information are known as

    1. replications.

    2. mutations.

    3. transformations.

    4. translations.

  2. A single-base mutation in a messenger RNA molecule could transcribe the DNA sequence CAGTAT into

    1. GTCATA.

    2. GUCAUA.

    3. GTCUTU.

    4. GUAAUA.

  3. A substance that can cause a change in the DNA code of an organism is called a

    1. toxin.

    2. mutagen.

    3. nitrogenous base.

    4. nucleotide.

  4. Name and give examples of two major types of mutations. What do they have in common? How are they different?

  5. How does a deletion mutation differ from a substitution mutation?

  6. Can mutations have a positive effect?

    Think Critically

  1. Compare and Contrast How does the possible impact of a chromosomal mutation that occurs during meiosis differ from that of a similar event that occurs during mitosis of a body cell that is not involved in reproduction?

  2. Apply Concepts A mutation in the DNA of an organism changes one base sequence in a protein-coding region from CAC to CAT. What is the effect of the mutation on the final protein? Explain your answer.

13.4 Gene Regulation and Expression

Understand Key Concepts

  1. An expressed gene

    1. functions as a promoter.

    2. is transcribed into RNA.

    3. codes for just one amino acid.

    4. is made of mRNA.

solve the CHAPTER MYSTERY

A mouse-eyed fly.

MOUSE-EYED FLY

Years ago geneticists discovered a fly gene they called eyeless. Mutations that inactivate this gene cause flies to develop without eyes. Geneticists later discovered a mouse gene, called Pax6, that was homologous to eyeless. Transplanting an activated Pax6 gene into a fruit fly can cause the fly to grow eyes in odd places. This happens despite the fact that mouse eyes and fly eyes are very different. In fact the only reason we describe them as “eyes” is because they make vision possible. How can the Pax6 gene perform the same role in such diverse animals? It probably began very early in the history of life, when eyes were just patches of light-sensitive cells on the skin of the common ancestors of all animals. As those organisms evolved and diversified, master control genes like Pax6 kept working, but with altered functions. Many genes like Pax6 are shared, not only by insects, but by all animals, including worms, sea urchins, and humans.

  1. Compare and Contrast How are fly eyes and mouse eyes different? Similar?

  2. Infer The Pax6 and eyeless genes code for transcription factors, not for parts of the actual eye. Why does this make sense in light of the effect of Pax6 when it is inserted into a fly?

  3. Connect to the What feature of the genetic code makes it possible for a mouse gene to work inside the cell of a fly?

End ofPage 387

Table of Contents

Miller & Levine Biology
About the Authors
Changing the World of Biology Education
Contents
Diversity of Life: A Visual Guide DOL•1–DOL•64
Labs and Activities
Features
UNIT 1 The Nature of Life
1 The Science of Biology
2 The Chemistry of Life
Unit Project
UNIT 2 Ecology
3 The Biosphere
4 Ecosystems and Communities
5 Populations
6 Humans in the Biosphere
Unit Project
UNIT 3 Cells
7 Cell Structure and Function
8 Photosynthesis
9 Cellular Respiration and Fermentation
10 Cell Growth and Division
Unit Project
UNIT 4 Genetics
11 Introduction to Genetics
12 DNA
13 RNA and Protein Synthesis
14 Human Heredity
15 Genetic Engineering
Unit Project
UNIT 5 Evolution
16 Darwin's Theory of Evolution
17 Evolution of Populations
18 Classification
19 History of Life
Unit Project
UNIT 6 From Microorganisms to Plants
20 Viruses and Prokaryotes
21 Protists and Fungi
22 Introduction to Plants
23 Plant Structure and Function
24 Plant Reproduction and Response
Unit Project
UNIT 7 Animals
25 Introduction to Animals
26 Animal Evolution and Diversity
27 Animal Systems I
28 Animal Systems II
29 Animal Behavior
Unit Project
UNIT 8 The Human Body
30 Digestive and Excretory Systems
31 Nervous System
32 Skeletal, Muscular, and Integumentary Systems
33 Circulatory and Respiratory Systems
34 Endocrine and Reproductive Systems
35 Immune System and Disease
Unit Project
A Visual Guide to The Diversity of Life
HOW TO USE THIS GUIDE
THE TREE OF LIFE
Bacteria
Protists
Fungi
Plants
Animals
Appendices
Appendix A Science Skills
Appendix B Lab Skills
Appendix C Technology & Design
Appendix D Math Skills
Appendix E Periodic Table
Glossary
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q, R
S
T
U
V
W
X, Y, Z
Index
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Credits
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